The present invention relates to an image sensing device, image signal processing method, an image sensing system, an image sensing apparatus, and a storage medium storing computer readable program codes of the method.
In an image signal processing circuit which deals with color signals, a variety of image signal processes, including compression, are usually performed. Generally, in the image signal processes, signals are processed by pixel blocks of a predetermined size.
There are various kinds of image signal processes which are performed by pixel blocks of the predetermined size, and code book information compression and expansion processes performed by comparing a pattern of pixel signals outputted from an image sensing device to codes stored as a code book, for instance, are included in such image signal processes.
In code book information compression and expansion processes, it is possible to improve precision of pattern (code) searching and processing speed by calculating, e.g., a maximum value, a minimum value, a difference between the maximum and minimum values, and addresses/address of pixels/pixel with the maximum and/or minimum value in each pixel block in advance of performing the pattern searching, and using these calculated values in the pattern searching.
When performing the calculation as described above, conventionally, pixel signals outputted from an image sensing device are processed by a signal processing circuit provided subsequently to the image sensing device. Therefore, in order to start processing the signals by pixel blocks, the signal processing circuit has to wait until all the pixel signals configuring each block are outputted from the image sensing device.
Further, memory is necessary for calculating a maximum value, a minimum value, a difference between the maximum and minimum values, addresses/address of pixels/pixel with the maximum and/or minimum value in each pixel block, and the required memory capacity is considerably large.
Therefore, neither good cost performance nor the high-speed image signal processing can be expected when a variety of image signal processes are to be performed in the conventional signal processing circuit.
The present invention has been made in consideration of the above situation, and has as its object to provide an image sensing device capable of outputting image signals suitable for image signal processes.
According to the present invention, the foregoing object is attained by providing an image sensing device comprising: a sensor unit having a plurality of pixels; control means for controlling to read signals from the sensor unit by pixel blocks of a first predetermined size; and signal processing means for calculating an address of a pixel with a distinctive value for each pixel block of the first predetermined size.
Further, the foregoing object is also attained by providing an image sensing device comprising: a sensor unit having a plurality of pixels; control means for controlling to read signals from the sensor unit by pixel blocks of a predetermined size; and signal processing means for calculating a difference between a plurality of distinctive values for each pixel block of the predetermined size, wherein the plurality of distinctive values are signals of different pixels in each pixel block.
Furthermore, the foregoing object is also attained by providing an image sensing device comprising: a sensor unit having a plurality of pixels; control means for controlling to read signals from the sensor unit by pixel blocks of a first predetermined size; and signal processing means for calculating distinctive information and performing operation between the distinctive information and each pixel in each pixel block of the first predetermined size.
Further, it is still another object of the present invention to provide an image sensing apparatus and an image sensing system using either of the aforesaid sensor units, an image processing method, and a computer readable storage medium storing program codes of the image processing method.
According to the present invention, the image sensing apparatus includes a sensor unit having a plurality of pixels; control means for controlling to read signals from the sensor unit by pixel blocks of a first predetermined size; signal processing means for calculating distinctive information of the signals, read from the sensor unit, for each pixel block of the first predetermined size; and compression means for compressing the read signals by the blocks of the first predetermined size using the distinctive information calculated by the signal processing means.
According to the present invention, the image processing method comprises a reading step of reading signals of a plurality of pixels by pixel blocks of a first predetermined size; and a signal processing step of calculating an address of a pixel with a distinctive value for each pixel block of the first predetermined size.
Further, the foregoing object is also obtained by providing an image signal reading and processing method comprising: a reading step of reading signals of a plurality of pixels by pixel blocks of a predetermined size; and a signal processing step of calculating a difference between a plurality of distinctive values for each pixel block of the predetermined size, wherein the plurality of distinctive values are signals of different pixels in each pixel block.
Furthermore, the foregoing object is also attained by providing an image signal reading and processing method comprising: a reading step of reading signals of a plurality of pixels by pixel blocks of a first predetermined size; and a signal processing step of calculating distinctive information and performing operation between the distinctive information and each pixel in each pixel block of the first predetermined size.
According to the present invention, the computer readable storage medium includes program codes of the steps of the aforesaid image processing method.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.